Author: Paul S. Weiland

Delta smelt have nearly ceased to appear in “pelagic” fish surveys carried out in their narrow geographic range in the upper San Francisco Estuary. As trawl-generated index values for delta smelt have declined over the past quarter century – understand there is no reliable estimate of the size of the delta smelt population — the chorus of voices advocating for captive rearing and releases of the species has grown louder. When in 2019 the Bureau of Reclamation proposed to include development of a conservation hatchery as a component of its ongoing operation of the federal Central Valley Project, it was building on work to culture delta smelt that was initiated […]
Conceptual models help us to understand the world around us without becoming overwhelmed with its complexity. Societal use of conceptual models is pervasive. Corporate organizational charts offer means to understand and express relationships within the business entity. Road maps represent transportation systems and the built environment. Depictions of food webs give insights into ecosystem structure, function, and composition. Conceptual ecological models are a specialized subset of conceptual models generally intended to describe the environmental factors that affect an ecological community, a species, or a population.  Conceptual ecological models are useful in a variety of contexts ranging from development of research proposals and monitoring schemes, to regulatory decision-making applied in the development […]
At this point there is well over a quarter century of research in the field of conservation biology assessing the wisdom of using surrogate species to guide conservation planning. Time and again researchers have warned of the risks associated with poorly informed use of surrogates, indicators, or proxy measures. A very recent example is an investigation by Fang Wang and colleagues, The hidden risk of using umbrella species as conservation surrogates: A spatio-temporal approach, published in Biological Conservation.   Wang and his colleagues evaluate use of the giant panda as an umbrella species to protect sympatric mammals, evaluating the panda and eight other mammal species using camera trap data, remote sensing […]
Oncorhynchus mykiss is perhaps the most popular freshwater sport fish in the United States. The geographic distribution of native Oncorhynchus mykiss within the lower 48 states is limited to a handful of states along and adjacent to the west coast — California, Oregon, Washington, and Idaho, although it extends south to Baja California and north to British Columbia and Alaska.  It is artificially propagated by federal and state fish and game agencies and in private aquaculture for game fishing purposes in hundreds of hatcheries and is now established in all of the 48 lower states, at least 45 countries, and every continent except Antarctica. Fly-fishing enthusiasts who live east of the Rockies might be surprised to […]
Choosing among alternative management actions to protect endangered species can be a fraught exercise in light of uncertainty about the outcomes. As Stefano Canessa and his colleagues point out in their article Risk aversion and uncertainty create a conundrum for planning recovery of a critically endangered species recently published in Conservation Science and Practice, the prospect is even more daunting when one or more of the alternatives has the potential to worsen the status of the species. That said, science has the potential to provide decision-makers with valuable information in such circumstances, thereby reducing uncertainty.   Canessa and his colleagues assess nest protection options for critically endangered regent honeyeaters, native […]
In recent years, the Department of Fish and Wildlife (Department) has taken steps to strengthen its science capacity in response to the enactment of AB 2402 by the Legislature and Governor in 2012. Among other things, AB 2402 required the Department and the Fish and Game Commission (Commission) to develop a strategic plan and authorized the Department to establish a Science Institute to inform the work of the Department and the Commission. To strengthen its science capacity, the Department developed a Scientific Integrity Policy in 2017. That Policy states “work that has a substantial scientific or management impact or large expenditure of funds or is especially controversial in nature should […]
After suing the federal government, in Spring 2020 the State of California sought an emergency injunction in federal district court requiring the U.S. Bureau of Reclamation to curtail water exports to central and southern California to protect steelhead migrating down the San Joaquin River and through the Sacramento-San Joaquin Delta on their way to the Pacific Ocean. The State argued that, if the Bureau failed to impose the San Joaquin River inflow to export ratio (referred to as the I:E ratio) in May 2020, it would undermine the overall prospects for recovery of the steelhead.
 In litigation in the same federal court less than a decade ago, the State argued […]


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